Formulae and Their Uses
Summaryarrow_upward
Formula
A formula consists of constants and variables.
In a formula the variables are interrelated. A formula is an equation that establishes a relationship among the variables involved in it. The plural form of formula is formulae.
Framing a formula:
Expressing a given statement in the form of an equation by using variables and mathematical symbols is called framing a formula.
Subject of a formula:
The subject of a formula is a variable that is expressed in terms of the other variables.
In other words, in a formula, the variable standing alone on one side of the equality sign is called the subject of the formula. The subject of a formula always lies on left hand side of the equality sign. The coefficient of the subject is always one. The subject of a formula does not link with any other quantities.
Changing the subject of a formula:
Any one variable of a formula can be made the subject by transferring the variables.
Evaluation of the subject of a formula (substitution method):
Finding the value of the subject by substituting the values of the other variables is called the evaluation of the subject of a formula.
Steps to evaluate the subject of a formula:

Make the required variable the subject.

Substitute the values of the other variables in the formula.

Simplify the formula.
Questions & Answersarrow_upward
1 . what is formula give some example
formula is estabilshing the relation among varabiles and constant involve in it
i think so.....
2 . Find the present ages of the father and his son.
nice question its easy so try to do it your self, i got the answer but you can do it your self easily
3 . What is the income of Ramesh?
Sol:
Let the income of Ramesh be Rs x.
Part of the income given to son = x/3
Part of the income given to daughter =...
4 . H=2/5nd2 .Find d, when H=1620and n=18
d=15
5 . What are the lenghts of the sides of the rectangle?
Sol:
Let the breadth of the rectanle be 'x' cm
Length of the rectangle = (x + 20) cm
Perimeter of the rectagle...
Or